Reinforced metal matrix composite

Abstract

A carbon fiber reinforced metal matrix composite is produced by depositing a metal boride coating on the surface of the fibers and subsequently immersing the fibers in a molten bath of the metal matrix material. The boride coating is formed by passing carbon fiber through a gaseous mixture of chlorides of the metal and boron in the presence of zinc vapor at elevated temperatures. The subsequent reaction deposits out a submicron lamina of metal boride on the carbon fibers serving to enhance wetting of the fibers by the molten metal, with the lamina preventing chemical reaction between the fibers and metal matrix materials and also providing a strong mechanical bond therebetween.

What is claimed is: 
     
       1. A carbon fiber reinforced metal matrix comprising: a continuous multifilament carbon fiber;   a metal boride film coating substantially all surfaces of the carbon fiber; and,   a metal matrix material infiltrated throughout and adhered to the multifilament fiber.   
     
     
       2. The carbon fiber reinforced metal matrix as defined in claim 1 wherein; the metal boride is titanium boride; and   the metal matrix material is aluminum or an aluminum alloy.   
     
     
       3. A composite product comprising a plurality of carbon fibers each have a coating of titanium boride, said fibers being disposed in a substantially solid matrix of metal selected from the group consisting of magnesium, lead, zinc, copper, aluminum, tin and alloys of said metals. 
     
     
       4. A composite as defined in claim 3 wherein the thickness of said coating is in the range of between 0.01 to 2.0 microns. 
     
     
       5. A composite as defined in claim 3 wherein said fibers are substantially graphite. 
     
     
       6. A composite as defined in claim 5 wherein said metal comprises aluminum. 
     
     
       7. A composite as defined in claim 5 wherein said metal comprises copper. 
     
     
       8. A composite as defined in claim 5 wherein said metal comprises lead.